The United States and Iran traded proposals over suspending Tehran's nuclear activities during weekend negotiations in Pakistan, but remain far apart on the length of any agreement, according to a report by The New York Times citing officials from both countries.

Iran signaled Monday it would be willing to halt uranium enrichment for up to five years, an offer the Trump administration rejected, according to two senior Iranian officials and one U.S. official who spoke to the Times.

The U.S. position, shaped in part by Vice President JD Vance, calls for a much longer suspension of about 20 years, a proposal Vance has previously advanced as necessary to permanently limit Iran's nuclear capabilities.

The sharp divide over timelines has emerged as the central obstacle in the talks, even as both sides move into more detailed negotiations.

The exchange of specific proposals marked a shift from earlier negotiations, when neither Washington nor Tehran had put concrete durations on the table.

Officials told the newspaper that the discussions nonetheless point to a possible path toward a broader agreement, despite the significant gap that remains.

The diplomatic push is unfolding alongside escalating military pressure, as the United States began a blockade of Iranian ports on Monday, according to a U.S. official cited by the Times.

That move threatens a fragile ceasefire that has held for nearly a week after recent regional fighting, raising concerns among negotiators that the talks could be derailed.

Iranian officials said their five-year proposal is intended as a confidence-building measure that preserves the country's right to a civilian nuclear program.

U.S. officials, speaking to the newspaper, countered that a shorter pause would only delay Iran's nuclear progress and fail to provide lasting security assurances.

President Donald Trump has backed the tougher U.S. stance, aligning with Vance's push for a longer-term restriction.

The talks in Pakistan involve regional intermediaries and remain fluid, with officials on both sides cautioning to the Times that no breakthrough is imminent.

Still, diplomats told the newspaper that negotiating specific terms represents a meaningful, if narrow, opening for a deal if the widening gap can be bridged.